Question

part 1 multiple choice: select the letter choice that best answers the question and record on your answer sheet. (2 pts each. 40 pts total)

1. the electron cloud has all of the following characteristics except

a. it is negatively charged. b. contains nearly all of the atoms mass.
c. it is divided into energy levels. d. contains nearly all of the atoms volume.

1. all electromagnetic waves have the same

a. wavelength b. frequency c. energy d. speed

1. states that as the atomic number increases, the attraction for electrons increases, and pulls the electrons in more tightly to the nucleus.

a. shielding effect b. ionization energy c. coulombs law d. oxidation numbers

1. the energy required to remove one electron from a neutral atom of an element is known as

a. electronegativity b. ionization energy
c. reactivity d. quantum energy

1. cations have electrons and thus have a charge.

a. lost; negative b. gained; negative
c lost; positive d. gained; positive

1. on the periodic table, the atomic radii of elements tend to increase as you move down a group and left in a period. why is this pattern occurring?

a. adding new electron shells b. increasing the distance between the nucleus and valence electrons
c. a weaker attraction for the outermost electron d. all the above

1. anions have electrons and thus have a charge.

a. lost; negative b. gained; negative
c. lost; positive d. gained; positive

1. consider the periodic trend seen for ionic radius. atoms that lose electrons tend to become. atoms th gain electrons tend to become

a. smaller; smaller b. larger; smaller
c. smaller; larger d. larger; larger

1. a(n) is an atom that has gained electrons in order to become stable.

a. anion b. cation c. coulombs law d. electron

1. a(n) is an atom that has lost electrons in order to become stable.

a. anion b. cation c. coulombs law d. electron

1. which of the following groups of elements would most likely have the greatest electronegativity?

a. halogens (group 17) b. alkali metals (group 1)
c. alkaline earth metals (group 2) d. transition metals (groups 3 - 12)

1. which of the following groups of elements would most likely have the least electronegativity?

a. halogens (group 17) b. alkali metals (group 1)
c. alkaline earth metals (group 2) d. transition metals (groups 3 - 12)

Explanation:

1. Electrons are negatively charged and occupy energy levels. The nucleus contains most of the atom's mass.
2. All electromagnetic waves travel at the speed of light in a vacuum.
3. Coulomb's Law describes the electrostatic attraction between charged particles (nucleus and electrons).
4. Ionization energy is the energy required to remove an electron from a neutral atom.
5. Cations lose electrons (become positively charged).
6. Moving down a group adds electron shells (increasing radius). Moving left in a period reduces effective nuclear charge (increasing radius).
7. Anions gain electrons (become negatively charged).
8. Losing electrons (cations) reduces electron - electron repulsion (smaller radius). Gaining electrons (anions) increases repulsion (larger radius).
9. Anions are atoms that have gained electrons.
10. Cations are atoms that have lost electrons.
11. Halogens (group 17) have high electronegativity (strong electron - attracting ability).
12. Alkali metals (group 1) have low electronegativity (weak electron - attracting ability).

Answer:

1. B. contains nearly all of the atom's mass.
2. D. speed
3. C. Coulomb's Law
4. B. ionization energy
5. C. lost; positive
6. D. all the above
7. B. gained; negative
8. C. smaller; larger
9. A. Anion
10. B. Cation
11. A. Halogens (group 17)
12. B. Alkali metals (group 1)